While on a trip to Valley of Fire in Nevada, I captured numerous Raw images using a polarized filter. Depending upon the angle of the shot (relative to the sun), certain parts of the sky are a darker, saturated blue compared to the rest of the sky. This is what I would expect from using a polarized filter.

My question, however, is how can I use the tools in Lightroom 5 to create a uniform blue sky? I've gotten unsatisfactory results using the Adjustment Brush.

In Photoshop I would use the eyedropper to take the darkest part of the sky, then use the brush tool in Darken mode at a fairly low opacity, say 20%, and with a large, soft brush I would paint in the darker area. That's the easiest approach, without masks and the like.

I run into that problem frequently. The gradient tool can handle it most of the time. You will have to fine tune the width of the transition area and reposition the gradient to suit the area you want to match. When you reposition, use the rotate arrow for alignment with the horizon, etc. Finally set the exposure slider to taste.Ken

I would use the radial gradient tool. Depending upon the extent of the problem, I might drag it our to a very large size with half of it off the image.

Seems like when I use either the Radial Filter or the Gradient Tool, I don't seem to get the smooth transition between the darker portion of the sky & the rest of the sky which is lighter. But that is likely due to the fact that I need to spend more time experimenting & tweaking the tools.